sys/dev/drm/drm_scatter.h

   1 /* drm_scatter.h -- IOCTLs to manage scatter/gather memory -*- linux-c -*-
   2  * Created: Mon Dec 18 23:20:54 2000 by gareth@valinux.com
   3  *
   4  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
   5  * All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the next
  15  * paragraph) shall be included in all copies or substantial portions of the
  16  * Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  22  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  23  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  24  * DEALINGS IN THE SOFTWARE.
  25  *
  26  * Authors:
  27  *   Gareth Hughes <gareth@valinux.com>
  28  *
  29  * $FreeBSD$
  30  */
  31
  32 #define __NO_VERSION__
  33 #include <linux/config.h>
  34 #include <linux/vmalloc.h>
  35 #include "dev/drm/drmP.h"
  36
  37 #define DEBUG_SCATTER 0
  38
  39 void DRM(sg_cleanup)( drm_sg_mem_t *entry )
  40 {
  41         struct page *page;
  42         int i;
  43
  44         for ( i = 0 ; i < entry->pages ; i++ ) {
  45                 page = entry->pagelist[i];
  46                 if ( page )
  47                         ClearPageReserved( page );
  48         }
  49
  50         vfree( entry->virtual );
  51
  52         DRM(free)( entry->busaddr,
  53                    entry->pages * sizeof(*entry->busaddr),
  54                    DRM_MEM_PAGES );
  55         DRM(free)( entry->pagelist,
  56                    entry->pages * sizeof(*entry->pagelist),
  57                    DRM_MEM_PAGES );
  58         DRM(free)( entry,
  59                    sizeof(*entry),
  60                    DRM_MEM_SGLISTS );
  61 }
  62
  63 int DRM(sg_alloc)( struct inode *inode, struct file *filp,
  64                    unsigned int cmd, unsigned long arg )
  65 {
  66         drm_file_t *priv = filp->private_data;
  67         drm_device_t *dev = priv->dev;
  68         drm_scatter_gather_t request;
  69         drm_sg_mem_t *entry;
  70         unsigned long pages, i, j;
  71         pgd_t *pgd;
  72         pmd_t *pmd;
  73         pte_t *pte;
  74
  75         DRM_DEBUG( "%s\n", __FUNCTION__ );
  76
  77         if ( dev->sg )
  78                 return DRM_OS_ERR(EINVAL);
  79
  80         if ( copy_from_user( &request,
  81                              (drm_scatter_gather_t *)arg,
  82                              sizeof(request) ) )
  83                 return DRM_OS_ERR(EFAULT);
  84
  85         entry = DRM(alloc)( sizeof(*entry), DRM_MEM_SGLISTS );
  86         if ( !entry )
  87                 return DRM_OS_ERR(ENOMEM);
  88
  89         memset( entry, 0, sizeof(*entry) );
  90
  91         pages = (request.size + PAGE_SIZE - 1) / PAGE_SIZE;
  92         DRM_DEBUG( "sg size=%ld pages=%ld\n", request.size, pages );
  93
  94         entry->pages = pages;
  95         entry->pagelist = DRM(alloc)( pages * sizeof(*entry->pagelist),
  96                                      DRM_MEM_PAGES );
  97         if ( !entry->pagelist ) {
  98                 DRM(free)( entry, sizeof(*entry), DRM_MEM_SGLISTS );
  99                 return DRM_OS_ERR(ENOMEM);
 100         }
 101
 102         entry->busaddr = DRM(alloc)( pages * sizeof(*entry->busaddr),
 103                                      DRM_MEM_PAGES );
 104         if ( !entry->busaddr ) {
 105                 DRM(free)( entry->pagelist,
 106                            entry->pages * sizeof(*entry->pagelist),
 107                            DRM_MEM_PAGES );
 108                 DRM(free)( entry,
 109                            sizeof(*entry),
 110                            DRM_MEM_SGLISTS );
 111                 return DRM_OS_ERR(ENOMEM);
 112         }
 113         memset( (void *)entry->busaddr, 0, pages * sizeof(*entry->busaddr) );
 114
 115         entry->virtual = vmalloc_32( pages << PAGE_SHIFT );
 116         if ( !entry->virtual ) {
 117                 DRM(free)( entry->busaddr,
 118                            entry->pages * sizeof(*entry->busaddr),
 119                            DRM_MEM_PAGES );
 120                 DRM(free)( entry->pagelist,
 121                            entry->pages * sizeof(*entry->pagelist),
 122                            DRM_MEM_PAGES );
 123                 DRM(free)( entry,
 124                            sizeof(*entry),
 125                            DRM_MEM_SGLISTS );
 126                 return DRM_OS_ERR(ENOMEM);
 127         }
 128
 129         /* This also forces the mapping of COW pages, so our page list
 130          * will be valid.  Please don't remove it...
 131          */
 132         memset( entry->virtual, 0, pages << PAGE_SHIFT );
 133
 134         entry->handle = (unsigned long)entry->virtual;
 135
 136         DRM_DEBUG( "sg alloc handle  = %08lx\n", entry->handle );
 137         DRM_DEBUG( "sg alloc virtual = %p\n", entry->virtual );
 138
 139         for ( i = entry->handle, j = 0 ; j < pages ; i += PAGE_SIZE, j++ ) {
 140                 pgd = pgd_offset_k( i );
 141                 if ( !pgd_present( *pgd ) )
 142                         goto failed;
 143
 144                 pmd = pmd_offset( pgd, i );
 145                 if ( !pmd_present( *pmd ) )
 146                         goto failed;
 147
 148                 pte = pte_offset( pmd, i );
 149                 if ( !pte_present( *pte ) )
 150                         goto failed;
 151
 152                 entry->pagelist[j] = pte_page( *pte );
 153
 154                 SetPageReserved( entry->pagelist[j] );
 155         }
 156
 157         request.handle = entry->handle;
 158
 159         if ( copy_to_user( (drm_scatter_gather_t *)arg,
 160                            &request,
 161                            sizeof(request) ) ) {
 162                 DRM(sg_cleanup)( entry );
 163                 return DRM_OS_ERR(EFAULT);
 164         }
 165
 166         dev->sg = entry;
 167
 168 #if DEBUG_SCATTER
 169         /* Verify that each page points to its virtual address, and vice
 170          * versa.
 171          */
 172         {
 173         int error = 0;
 174
 175         for ( i = 0 ; i < pages ; i++ ) {
 176                 unsigned long *tmp;
 177
 178                 tmp = page_address( entry->pagelist[i] );
 179                 for ( j = 0 ;
 180                       j < PAGE_SIZE / sizeof(unsigned long) ;
 181                       j++, tmp++ ) {
 182                         *tmp = 0xcafebabe;
 183                 }
 184                 tmp = (unsigned long *)((u8 *)entry->virtual +
 185                                         (PAGE_SIZE * i));
 186                 for( j = 0 ;
 187                      j < PAGE_SIZE / sizeof(unsigned long) ;
 188                      j++, tmp++ ) {
 189                         if ( *tmp != 0xcafebabe && error == 0 ) {
 190                                 error = 1;
 191                                 DRM_ERROR( "Scatter allocation error, "
 192                                            "pagelist does not match "
 193                                            "virtual mapping\n" );
 194                         }
 195                 }
 196                 tmp = page_address( entry->pagelist[i] );
 197                 for(j = 0 ;
 198                     j < PAGE_SIZE / sizeof(unsigned long) ;
 199                     j++, tmp++) {
 200                         *tmp = 0;
 201                 }
 202         }
 203         if (error == 0)
 204                 DRM_ERROR( "Scatter allocation matches pagelist\n" );
 205         }
 206 #endif
 207
 208         return 0;
 209
 210  failed:
 211         DRM(sg_cleanup)( entry );
 212         return DRM_OS_ERR(ENOMEM);
 213 }
 214
 215 int DRM(sg_free)( struct inode *inode, struct file *filp,
 216                  unsigned int cmd, unsigned long arg )
 217 {
 218         drm_file_t *priv = filp->private_data;
 219         drm_device_t *dev = priv->dev;
 220         drm_scatter_gather_t request;
 221         drm_sg_mem_t *entry;
 222
 223         if ( copy_from_user( &request,
 224                              (drm_scatter_gather_t *)arg,
 225                              sizeof(request) ) )
 226                 return DRM_OS_ERR(EFAULT);
 227
 228         entry = dev->sg;
 229         dev->sg = NULL;
 230
 231         if ( !entry || entry->handle != request.handle )
 232                 return DRM_OS_ERR(EINVAL);
 233
 234         DRM_DEBUG( "sg free virtual  = %p\n", entry->virtual );
 235
 236         DRM(sg_cleanup)( entry );
 237
 238         return 0;
 239 }